Architectural design firm WORKac, have completed the renovation of a historical building with a cast-iron facade in New York City, and transformed it into modern apartments.

From the exterior, and only visible when looking down on it, is the rooftop addition, which New York City’s Landmarks Commission required to be invisible from the street level. However as the building is low compared to others around it, the designers had to get creative.

They utilized three rooftop projections to mask the bulk of an addition: the triangular pediment of the historic Carey Building next door, and the circular pediment and an abandoned elevator bulkhead at the top of the building itself. The “shadow” created by these three projections created a zone for the addition and the opportunity for a distinctive angled form for the new roof.